| Taxonomy
and Pathology of Togninia (Diaporthales) and its
Phaeoacremonium Anamorphs
Lizel Mostert1,2, Johannes
Z. Groenewald1, Richard C. Summerbell1,
Walter Gams1 and Pedro W. Crous1
1Centraalbureau voor Schimmelcultures,
P.O. Box 85167, 3508 AD Utrecht, The Netherlands; 2Current
address: Department of Plant Pathology, University of Stellenbosch,
Private Bag X1, Stellenbosch 7602, South Africa.
Abstract
The genus Togninia (Diaporthales,
Togniniaceae) is here monographed along with its
Phaeoacremonium (Pm.) anamorphs. Ten
species of Togninia and 22 species of Phaeoacremonium
are treated. Several new species of Togninia
(T.) are described, namely T. argentinensis
(anamorph Pm. argentinense), T. austroafricana
(anamorph Pm. austroafricanum), T. krajdenii,
T. parasitica, T. rubrigena and T. viticola.
New species of Phaeoacremonium include Pm.
novae-zealandiae (teleomorph T. novae-zealandiae),
Pm. iranianum, Pm. sphinctrophorum and Pm.
theobromatis. Species can be identified based on
their cultural and morphological characters, supported
by DNA data derived from partial sequences of the actin
and  -tubulin
genes. Phylogenies of the SSU and LSU rRNA genes were
used to determine whether Togninia has more
affinity with the Calosphaeriales or the Diaporthales.
The results confirmed that Togninia had a higher
affinity to the Diaporthales than the Calosphaeriales.
Examination of type specimens revealed that T. cornicola,
T. vasculosa, T. rhododendri, T. minima var. timidula
and T. villosa, were not members of Togninia.
The new combinations Calosphaeria cornicola, Calosphaeria
rhododendri, Calosphaeria transversa, Calosphaeria tumidula,
Calosphaeria vasculosa and Jattaea villosa
are proposed. Species of Phaeoacremonium are
known vascular plant pathogens causing wilting and dieback
of woody plants. The most prominent diseases in which
they are involved are Petri disease and esca, which
occur on grapevines and are caused by a complex of fungi,
often including multiple species of Phaeoacremonium.
Various Phaeoacremonium species are opportunistic
fungi on humans and cause phaeohyphomycosis. The correct
and rapid identification of Phaeoacremonium
species is important to facilitate the understanding
of their involvement in plant as well as human disease.
A rapid identification method was developed for the
22 species of Phaeacremonium. It involved the
use of 23 species-specific primers, including 20 primers
targeting the -tubulin
gene and three targeting the actin gene. These primers
can be used in 14 multiplex reactions. Additionally,
a multipleentry electronic key based on morphological,
cultural and -tubulin
sequence data was developed to facilitate phenotypic
and sequence-based species identification of the different
Phaeoacremonium species. Separate dichotomous
keys are provided for the identification of the Togninia
and Phaeoacremonium species. Keys for the identification
of Phaeoacremonium-like fungi and the genera
related to Togninia are also provided. The
mating strategy of several Togninia species
was investigated with ascospores obtained from fertile
perithecia produced in vitro. Togninia argentinensis
and T. novae-zealandiae have homothallic mating
systems, whereas T. austroafricana, T. krajdenii,
T. minima, T. parasitica, T. rubrigena and T.
viticola were heterothallic.
Keywords:Actin;-tubulin;
BioloMICS;Calosphaeriales;LSU;morphology;Phaeoacremonium;
phylogeny; SSU; systematics; Togninia; Togniniaceae;taxonomy.
Corresponding author:
E-mail: Lizel
Mostert, lmost@sun.ac.za |
